Servicing device for vehicle air-conditioning systems and method for operating said device

ABSTRACT

The invention relates to a servicing device for vehicle air-conditioning systems comprising an evacuation assembly for withdrawing the coolant/compressor oil mixture from the coolant circuit of a vehicle air-conditioning system and comprising a coolant gas analyzer. In said device, a gas analysis connection is provided on or in at least one of the connection lines between the servicing device and the vehicle air-conditioning system. Said gas analysis connection is fluidically connected or can be fluidically connected to the coolant gas analyzer via an oil separator that can be evacuated and that is connected at least at intervals to an evacuation assembly.

FIELD OF THE INVENTION

The invention relates to a servicing device for vehicle air-conditioningsystems with upstream refrigerant gas analysis having the features ofthe preamble of claim 1, and to a method for operating said device.Accordingly, a servicing device for vehicle air-conditioning systemscomprises at least one emptying device for extracting therefrigerant/compressor oil mixture from the refrigerant circuit systemof a vehicle air-conditioning system, and a refrigerant gas analyzer. Asis known per se, at least one compressor oil separator, a refrigerantcompressor, a separator stage, a refrigerant weighing device, a vacuumpump for emptying the residual contents of the refrigerant circuitsystem of the vehicle air-conditioning system and/or at least onepressure-controlled and/or time-controlled switchover valve block foroptionally directly connecting the refrigerant circuit system of thevehicle air-conditioning system fluidically to the separator stage or toa refilling system for refilling the vehicle air-conditioning systemwith refrigerant, compressor oil and possibly additive can preferablyalso be provided.

TECHNOLOGICAL BACKGROUND

Servicing devices for vehicle air-conditioning systems serve, interalia, within the context of maintenance, to empty the refrigerantcircuit of a very wide variety of vehicle air-conditioning systems fromtime to time and to introduce a new refrigerant filling. It is necessaryhere to maintain precise quantities and refrigerant specifications.Moreover, in many cases lubricant for the compressor of the refrigerantcircuit of the vehicle air-conditioning system has to be removed and asa rule refilled again. This also takes place in quantities andspecifications which are dependent on the vehicle type and/orair-conditioning unit type. Moreover, some vehicle air-conditioningsystems require an additive for the refrigerant circuit, which additiveis likewise replaced at least partially during a maintenance service.The compressor oil usually passes into the refrigerant circuit and istherefore also circulated during operation of the vehicleair-conditioning systems. Only very specific pairings of refrigerant andcompressor oil are compatible with one another for this purpose. Inorder for it to be possible, after the extraction of therefrigerant/compressor oil mixture, to recover at least part, preferablythe predominant part, of the refrigerant for re-use, servicing units forvehicle air-conditioning systems usually also have a separator, by wayof which refrigerant can be separated from the refrigerant/compressoroil mixture for re-use (compressor oil separator). Used compressor oiland, optionally, used additive is/are collected as a rule by theservicing device, in order to be discarded or reused later.

WO 2007/085480 from the applicant has disclosed a servicing device forvehicle air-conditioning systems in accordance with the block circuitdiagram according to FIG. 1. With a solid line, said figure shows theessential constituent parts of a usual servicing device for a vehicleair-conditioning system and, with dashed lines, shows a vehicleair-conditioning system to be maintained. The latter comprises anoil-lubricated compressor 1′, a condenser 2′, an evaporator 3′, andpipelines 4A′-4C′ which produce a closed coolant system between saidcomponents. Furthermore, a dryer 5′ is provided which can also serve ascollector or reservoir for refrigerant. Finally, two servicingconnections 6A′/6B′ are installed into the refrigerant circuit for theexchange of fluid. The cold which is available at the evaporator 3′ isled away by a cold air fan 7′ and fed to the vehicle interior. Thecondensation heat of the condenser 2′ is transported away by a warm airfan 8′. Servicing connection connectors 9A′ and 9B′ allowrefrigerant/compressor oil mixture to be drawn off or filled at theservicing connections 6A′, 6B′ in the case of maintenance. The vehicleair-conditioning system which is denoted overall by 10′ differs fromvehicle type to vehicle type and is not the subject matter of thepresent invention.

The servicing device which is denoted overall by 20′ for a vehicleair-conditioning system has flexible pressure hoses 11A′, 11B′ forconnecting the servicing unit 20′ to the vehicle air-conditioning system10′ via the servicing connection connectors 9A′, 9B′ at the servicingconnections 6A′, 6B′. An exhaust pump 12′ which is configured as arefrigerant compressor conveys used refrigerant/compressor oil mixturevia the pressure hoses 11A′ and 11B′ and the separator 14′. The latterseparates refrigerant from the extracted mixture by way of evaporationand feeds it to a refrigerant store 15′ which is configured as apressure container. Compressor oil/additive mixture which is separatedin the separator 14′ is collected in an exchangeable waste oil container16′ and is weighed by means of a weighing device 17A′. An air-cooledrefrigerant condenser 15A′ is connected fixedly to the refrigerant store15′. Returned refrigerant is therefore fed predominantly in liquid formto the refrigerant store 15′. The entire refrigerant store includingcondenser rests on a further weighing device 17B′ for detecting therefrigerant which is fed in and is led away and also the availablerefrigerant. After the extraction of the used mixture, a vacuum pump 13′provides the vacuum which is required for refilling in the circuit ofthe vehicle air-conditioning system and discharges the extracted gasvolume to the atmosphere.

A refilling system which is denoted overall by 19′ comprisessubstantially exchangeable storage vessels 19D′ for compressor oil and19C′ for additives, a control unit 19A′ with valve block and controllines 19B′, a remote indication 19E′ and metering and valve units 19F″to 19F″″. The storage vessels 19C′ and 19D′ can preferably be weighed.Further weighing devices 17C′, 17D′ serve for this purpose.

DE 20 2008 003 123 U1 has disclosed a further servicing device forvehicle air-conditioning systems from the applicant, in which therefilling capability of the previously evacuated vehicleair-conditioning system is improved by a heat source, provided in therefrigerant storage vessel, for increasing the pressure of therefrigerant. A comparable servicing device for vehicle air-conditioningsystems is known from US 2009/0158756A1.

In a further servicing device of the generic type for vehicleair-conditioning systems from the applicant, DE 2009 054 446 which isstill unpublished and was filed on Nov. 25, 2009 has disclosed, in afirst maintenance phase, to extract a circuit mixture of refrigerant,compressor oil and optionally further mixture constituent parts from avehicle air-conditioning system into a separator stage by means of arefrigerant compressor via a separator and in the process to separate,compress and collect refrigerant by means of the separator from theextracted circuit mixture, and to determine its quantity. In a secondmaintenance phase, the refrigerant circuit system of the vehicleair-conditioning system has its remaining contents largely removed bymeans of a vacuum pump. Residual gases which are pumped out in thesecond maintenance phase are guided by means of the refrigerantcompressor through the separator stage and the quantity of the remainingrefrigerant which is collected in the process is determined. Thediagnosis of the state of the vehicle air-conditioning system, interalia, is improved by way of this measure.

In order to avoid a refrigerant which is, for example, used erroneouslythere from passing from a vehicle air-conditioning system to bemaintained into the servicing device, which refrigerant is notcompatible with the remaining refrigerant/refrigerants extracted by theservicing device and stored in it, gas analysis devices for refrigerantto be extracted have been used since relatively recently. One of thedisadvantages comprises the fact that the accuracy of the analysisfluctuates as a rule and the analysis device therefore has to be testedfrequently.

SUMMARY OF THE INVENTION

Proceeding from this, the invention is based on the object of improvingthe stability of the accuracy of the analysis in a servicing device forvehicle air-conditioning systems with upstream refrigerant gas analysis.

In order to solve the problem on which the invention is based, aservicing device of the generic type for vehicle air-conditioningsystems having the features of claim 1 and a method having the featuresof claim 4 are proposed. Accordingly, a gas analysis connection isprovided on or in at least one of the connecting lines between theservicing device and the vehicle air-conditioning system. Said gasanalysis connection is connected or can be connected fluidically to thegas analyzer for refrigerant via an oil separator which can be evacuatedand is connected at least temporarily to an evacuating device.

The invention proceeds from the finding that the presence of compressoroil in the refrigerant to be exchanged represents a substantial cause ofmalfunctions of the analysis device.

If the oil separator can be connected to a separator stage forrefrigerant/compressor oil mixture, the sample of refrigerant/compressoroil mixture which is drawn from the vehicle air-conditioning system forthe purpose of refrigerant gas analysis can be treated further in thesame way as the refrigerant/compressor oil mixture which accumulatesduring emptying of the vehicle air-conditioning system and, inparticular, refrigerant can be recovered.

If the region of the connecting lines between the oil separator andservice connection connectors of the servicing device can be emptied ofrefrigerant/compressor oil mixture via connectors, the servicing devicecan be protected as a result in a simple way against refrigerants and/orcompressor oils which are not accepted.

By way of the invention, the predominant part of therefrigerant/compressor oil mixture which is present for sample-takingfor the gas analysis can be separated from compressor oil components inan integrated process with an extremely justifiable outlay. As a result,malfunctions of the gas analyzer and/or fluctuating analysis values areruled out as far as possible, without it being necessary for complicatedmaintenance work to be carried out for this purpose. If required, a gasanalysis means according to the invention can be retrofitted into anexisting servicing device for vehicle air-conditioning systems, inparticular as a module. A preliminary setup which is already providedfor this purpose, for example in the form of suitable connection points,is helpful.

The abovementioned components and the claimed components which aredescribed in the exemplary embodiments and are to be used according tothe invention are not subject to any special exceptional conditions interms of their size, shape, material selection and technical design,with the result that the selection criteria which are known in the fieldof use can be used in an unrestricted manner.

Further details, features and advantages of the subject matter of theinvention result from the subclaims, and from the following descriptionand the associated drawing, in which one exemplary embodiment of aservicing device for vehicle air-conditioning systems is shown by way ofexample. Individual features of the claims or the embodiments can alsobe combined with other features of other claims and embodiments.

BRIEF DESCRIPTION OF THE FIGURES

In the drawing:

FIG. 2 shows a servicing device for vehicle air-conditioning systems asa block circuit diagram, in a basic position,

FIG. 3 shows the same servicing device in the evacuating phase of an oilseparator (156),

FIG. 4 shows the same servicing device in the filling phase of the oilseparator (156),

FIG. 5 shows the same servicing device in the sample-taking phase of theanalyzer (161),

FIG. 6 shows the same servicing device in the analysis phase of theanalyzer (161),

FIG. 7 shows the same servicing device in the emptying phase of the oilseparator (156), after approval of the analyzed refrigerant, and

FIG. 8 shows the same servicing device in the emptying phase of the oilseparator (156), after rejection of the analyzed refrigerant.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The basic construction of a servicing device of the generic type forvehicle air-conditioning systems results from the block circuit diagramaccording to FIG. 2, not all the components which are shown beingnecessary constituent parts of the present invention, however.Accordingly, servicing connection connectors 109A, 109B are provided forconnection to the coolant/compressor oil circuit of a vehicleair-conditioning system (not shown here), in order to service thelatter, in particular to empty it and refill it. There is a fluidicconnection via pressure hoses 111A, 111B to a first switchover valveblock 130, the function of which will be explained further below. Theswitchover valve block 130 is connected fluidically firstly to aseparator stage 140 which is shown on the right in the figure and willbe explained further below, and secondly (at the bottom left in thefigure) to a vacuum unit 150 which will likewise be explained furtherbelow. A low pressure manometer 126A and a high pressure manometer 126B,connected to the switchover valve block 130, serve, inter alia, to checkthe state and function of the coolant/compressor oil circuit of thevehicle air-conditioning system. Furthermore, the switchover valve block130 is connected fluidically to a refilling system 119 for compressoroil and additives, having weighing devices 117C and 117D for dispensers119C, 119D, for example for an additive for leak search and for freshoil, respectively. The system pressure within the switchover valve block130, which is of significance for the system controller which will beexplained further below after emptying has begun of the fluid circuit,is monitored via a pressure sensor 131A which is connected to acollecting line 130A of the switchover valve block 130, with the resultthat the system pressure, in particular the refrigerant pressure of thevehicle air-conditioning system is monitored, as a result of which,inter alia, the circuit systems which are explained in the followingtext (separator stage 140 and vacuum unit 150 and associated valvecircuits) can be controlled.

The method of operation of the separator stage 140 is as follows: afterconnection of the servicing connection connectors 109A, 109B to thecorresponding ports of the vehicle air-conditioning system and openingof the corresponding valves LP, HP, Z2 of the switchover valve block130, the system pressure of the vehicle air-conditioning system isavailable, in order to transfer a first part of the contents of therefrigerant/compressor oil circuit of the vehicle air-conditioningsystem into the separator stage 140. Said system pressure is alreadyapproximately 3 bar absolute at 0° C. and is already in an order ofmagnitude of 6 bar absolute at approximately 20° C., with the resultthat, as in the filling phase according to FIG. 4, for example, theconveying of refrigerant/compressor oil mixture takes place. The initialemptying of the vehicle air-conditioning systems (not shown) toward theseparator stage 140 can likewise first of all take place automatically.Otherwise, this conveying is assisted by operation of a compressor 112,as explained further below, and is later kept further in motion when thesystem pressure drops. From the switchover valve block 130, therefrigerant/compressor oil mixture passes via a coarse filter 114 and aconstant pressure valve 141 which is set to approximately 3.5 barabsolute into a jacketed heat exchanger 142, to be precise into theinner container 142A thereof. There the volatile components areevaporated and the gas phase passes via a line 146A into a gas-dryingapparatus 146 and from there into the compressor 112.

The jacketed heat exchanger 142 serves at the same time as a separatorfor liquid constituent parts of the refrigerant/compressor oil mixture;these are essentially the compressor oil, any additives which arecontained and residual quantities of the refrigerant which are stillbound in the compressor oil. This liquid phase is fed via an oildischarge valve 116A to a waste oil container 116. The quantities whichaccumulate can be registered via a weighing device 117A which alsoweighs the container.

The compressor 112 ensures that, at its output side, the refrigerant iscompressed to a pressure of up to, for example, 19 bar absolute. Acompressor emergency shut-off valve 112A limits the pressure as a ruleto 19 bar. Since the lubricating oil of the compressor 112 also passesinto the compressed refrigerant, it is separated in a (first) oilseparator 112B and is fed via a capillary tube 112C which acts like apressure throttle to the lubrication means of the compressor 112 again.Via a solenoid valve 112D, the compressed, dried refrigerant which isfreed from compressor oil and additives passes into a heating coil 142Cwhich is situated in the gas space of the inner container 142A of thejacketed heat exchanger 142. As a result, the heat of compression whichis contained in the compressed refrigerant can be dissipated, in orderto evaporate the refrigerant/compressor oil mixture which arrivesfreshly from the vehicle air-conditioning system as far as possible onthe cold side. From the heating coil 142C, the purified (recycled)refrigerant passes first of all into the outer jacket region (outercontainer 142B) of the jacketed heat exchanger 142 and from there via avalve block 142D and a connecting hose 129 to the refrigerant store 115(storage vessel).

The storage vessel including contents is weighed by a weighing device117B. The storage vessel also carries a refrigerant condenser 115A whichis also advantageously weighed and in which the refrigerant which isunder compression pressure is condensed, in order to pass in liquid forminto the refrigerant store 115. Both the (first) separator 112B and therefrigerant store 115 are designed as what are known as pressurevessels. The pressure in the refrigerant store 115 is secured againstoverpressure via a valve 115B because the gas phase, which forms abovethe liquid level, of gases which cannot be condensed has to bedischarged in a regulated manner for safety reasons above a definedoverpressure of, for example, 16 bar. This can also take place in anon-automatic manner via a handle 115C by an operator.

The liquid refrigerant passes via a nonreturn valve 115D and a riserpipe 115E into the liquid region of the refrigerant store 115. In orderfor it to be possible to refill the vehicle air-conditioning system withrefrigerant, liquid refrigerant passes via the riser pipe 115E, a valve115F and a connecting line 115G back into the switchover valve block130, preferably into its collecting line.

As soon as the vehicle air-conditioning system is emptied to such anextent that the compressor 112 can no longer suck in sufficientrefrigerant/compressor oil mixture on its low pressure side, which canbe the case, for example, at a pressure of 0.7 bar absolute, the vacuumunit 150 is started, optionally by actuation of the correspondingvalves. Further gas constituent parts are thus sucked out of the fluidcircuit of the vehicle air-conditioning system by the collecting line ofthe switchover valve block 130 by the vacuum pump 113. From the outletside of the vacuum pump 113, this gas or gas mixture passes via a(second) switchover valve block 151 and solenoid valves AU into theconnecting line 143 which couples the switchover valve block 130fluidically to the separator stage 140. The gas quantities which areconveyed by the vacuum pump 113 from the vehicle air-conditioning systemare then treated in the separator stage 140 in exactly the same wayincluding weighing as the quantities of refrigerant/compressor oilmixture which exit the vehicle air-conditioning system automatically atthe beginning of the emptying process. The difference from the firstphase, called outflow phase here, consists in the fact that no liquidconstituent parts are sucked out of the vehicle air-conditioning systemon account of the preceding outflow phase which is assisted by thecompressor 112, that is to say that substantially only gaseousrefrigerant or optionally air is still sucked out of the vehicleair-conditioning system. Relatively large gas quantities are to be dealtwith first of all here. Toward the end of the second phase, called theevacuating phase here, the gas quantities become considerably smaller,however. At an inlet pressure of approximately 1 mbar or after a processtime which has been preset fixedly has elapsed, the evacuating processis ended.

The gas pressure which is generated by the vacuum pump 113 on its outletside should not exceed an order of magnitude of 2 bar absolute, in ordernot to damage the vacuum pump 113. For pressure checking, the switchovervalve block 151 which is connected downstream of the vacuum pump isassigned a pressure switch 151A, with the aid of which the vacuum pump113 switches off if an outlet pressure of, for example, 2 bar isexceeded, until the outlet pressure has again dropped correspondingly,with the result that the vacuum pump 113 can be switched on again.

Since the servicing device can be used not only for extracting andrefilling the vehicle air-conditioning system in normal maintenanceoperation, but rather can also be used for cases of repair toair-conditioning systems, for example the exchange of components, theswitchover valve block 151 which is connected downstream of the vacuumpump 113 is equipped with a discharge valve VO which can lead, forexample, into the atmosphere. If merely air is therefore sucked out ofthe repaired vehicle air-conditioning system for subsequent refilling,this does not necessarily have to pass into the separator stage 140.

At or close to its upper end, a (second) oil separator 156 which can beevacuated is connected fluidically to the low-pressure side via aconnecting line 157A which can be shut off and, for example, a shut-offvalve 156A and (not shown) optionally 156B which can be actuatedautomatically or is operated by hand, in a first (shown) embodiment,close to or, in the exemplary embodiment, on the inlet side of the firstswitchover valve block 130.

At or close to its lower end, the oil separator 156 can be connectedfluidically to the suction side of the vacuum pump 113 via at least onefurther shut-off valve 156C and (not shown) optionally 156D and aconnecting line 157B, and further via the first switchover valve block130 and its collecting line 130A. A direct flow connection can thereforebe produced between the oil separator 156 which can be evacuated and thevacuum pump 113. The connecting line 157B preferably also has a flowconnection to the waste oil container 116, in particular at a lineregion 157C which is inclined downward, with the result that compressoroil which accumulates in the second oil separator 156 can also bereceived directly by the waste oil container 116.

The method of operation is as follows: at the beginning of a refrigerantexchange, the servicing connection connectors 109A, 109B are coupledfluidically to the corresponding coupling points of the refrigerantcircuit of a vehicle air-conditioning system. An evacuating routine forthe (second) oil separator 156 is then carried out, as can be seen inbold lines from FIG. 3. To this end, the shut-off valves 156A and 161Bare closed, optionally automatically, and the shut-off valve 156C iskept open or is opened, preferably electrically. Shut-off valves 156Aand optionally 156B (not shown) upstream of the oil separator 156 and/orshut-off valves 156C and optionally 156D downstream of the oil separator156 can (in principle) be replaced by a single shut-off valve (156A or156C), as shown. In the above-described way, the oil separator 156 canbe evacuated and its internal pressure can be reduced to, for example, 1mbar absolute. The short lines upstream of the oil separator 156 towardsaid shut-off valve/valves are likewise evacuated, with the result thatthere are no gases which distort the later analysis, above all in theoil separator 156. Any residues of compressor oil are transferred out ofthe oil separator 156 into the waste oil container 116.

In the following work step, the sample provision, as indicated by thebold lines in FIG. 4, the oil separator 156 is shielded toward thevacuum pump 113 by closure of the shut-off valve 156C, and is connectedfluidically via the connecting line 157A to the gas analysis connection161A and the low pressure line, such as the pressure hose 111A, byopening of the shut-off valve 156A. The oil separator 156 is thereforealso connected in a fluidically conducting manner to the servicingconnection connector 109A of the low pressure side and the vehicleair-conditioning system which is connected upstream. As a result of thepositive pressure which prevails as a rule in the vehicleair-conditioning system at the beginning, but at any rate on account ofthe vacuum in the oil separator 156, refrigerant/compressor oil mixturethen flows over into the oil separator 156 until its internal pressureis equalized with that of the vehicle air-conditioning system, or untilthe shut-off valve 156A is closed again. At any rate, it is awaited as arule until a certain positive pressure prevails in the oil separator156. The liquid phase of the refrigerant/compressor oil mixture settlesin the bottom region at the lower end of the oil separator 156 as earlyas during the flow of used refrigerant/compressor oil mixture over intothe oil separator 156 and also after closure of its shut-off valve 156Awhich is situated upstream, whereas evaporated refrigerant and possiblyair are situated in the gas phase which is formed above said liquidlevel. The degree of separation is preferably 99% or better, but shouldat least lie above 90%.

In the next work phase, as shown in FIG. 5 by bold lines, the oilseparator 156 is connected fluidically to the gas analyzer 161 byopening of the inlet-side shut-off valve 161B. As a result of thepositive pressure which prevails in the gas phase of the oil separatoras a rule, refrigerant gas and possibly air, but no compressor oil, thenflows over into the gas analyzer 151. The gas analyzer 161 can have adedicated pump (not shown) which is known per se, in order to sucksample gas into the gas analyzer. The gas analysis is carried out (FIG.6) as early as during the flow over of the sample gas or else, aspreferred, after fluidic separation of the oil separator 156 from thegas analyzer 161 by closure of the shut-off valve 161B, and the testedrefrigerant sample is subsequently discharged from the analyzer.

If the gas analyzer 161 accepts the refrigerant gas, the refrigerantwhich is present in the oil separator 156 and the compressor oil canthen be extracted, as shown by way of bold lines in FIG. 7, by theshut-off valve 156C being opened again. However, the mixture which isextracted in the process is preferably not discharged into theatmosphere, but rather is fed by the vacuum pump 113 via the secondvalve block 151 and a connecting line 143 to the jacketed heat exchanger142, in order to separate the compressor oil into the waste oilcontainer 116 and to recover the refrigerant in the same way as takesplace during the step of emptying the vehicle air-conditioning system.Here, as has already been mentioned further above in conjunction withFIG. 2, the compressor oil can also be received directly by the wasteoil container 116 via the connecting line 157B and a flow connection tothe waste oil container 116, in particular at a line region 157C whichis inclined downward. Otherwise, the refrigerant/compressor oil mixturepasses via the first valve block 130 into the separator stage 140 and istreated there, as has already been explained in greater detail inconjunction with FIG. 2.

If, in contrast, the gas analyzer 161 does not accept the refrigerantsample which was obtained from the vehicle air-conditioning system, therefrigerant/compressor oil mixture must not flow, or must not flowfurther, from the vehicle air-conditioning system into the servicingdevice 100. In this case, as shown by way of bold lines in FIG. 8, therefrigerant/compressor oil mixture is returned via the connecting line157A and the gas analysis connection 161A and is discharged viaconnectors 162A, 162B on the pressure hoses 111A, 111B or their end-sideconnections from the vehicle air-conditioning system and the oilseparator 156 to a further reclamation means, and also does not pass, ordoes not pass further, into the switchover valve block 130.

LIST OF DESIGNATIONS

-   -   1′ Compressor    -   2′ Condenser    -   3′ Evaporator    -   4A′-C′ Pipelines    -   5′ Separator    -   6A′/B′ Servicing connections    -   7′ Cold air fan    -   8′ Warm air fan    -   9A′/B′ Servicing connection connectors    -   10′ Vehicle air-conditioning system    -   11A′/B′ Pressure hoses    -   12′ Exhaust pump    -   13′ Vacuum pump    -   14′ Separator    -   15′ Refrigerant store    -   15A′ Refrigerant condenser    -   16′ Waste oil container    -   17A′-J′ Weighing devices    -   18′ Relief device    -   19′ Refilling system    -   19A′ Control unit with valve block    -   19B′ Control lines    -   19C′ Storage vessel    -   19D′ Storage vessel    -   19E′ Remote indication    -   19F″ Metering and valve unit    -   19F″′ Metering and valve unit    -   19F″′ Metering and valve unit    -   20′ Servicing device    -   26A′ Low pressure manometer    -   26B′ High pressure manometer    -   100 Servicing device    -   109A Servicing connection connector    -   109B Servicing connection connector

111A Pressure hoses

-   -   111B Pressure hoses    -   112 Compressor    -   112A Compressor emergency shut-off valve    -   112B (First) oil separator    -   112C Capillary tube    -   112D Solenoid valve    -   113 Vacuum pump    -   114 Coarse filter    -   115 Refrigerant store    -   115A Refrigerant condenser    -   115B Valve    -   115C Handle    -   115D Nonreturn valve    -   115E Riser pipe    -   115F Valve    -   115G Connecting line    -   116 Waste oil container    -   116A Oil discharge valve    -   117A Weighing device    -   117B Weighing device    -   117C Weighing device    -   117D Weighing device    -   119 Refilling system    -   119C Dispenser    -   119D Dispenser    -   126A Low pressure manometer    -   126B High pressure manometer    -   129 Connecting hose    -   130 First switchover valve block    -   130A Collecting line    -   131A Pressure sensor    -   140 Separator stage    -   141 Constant pressure valve    -   142 Jacketed heat exchanger    -   142A Inner container    -   142B Outer container    -   142C Heating coil    -   142D Valve block    -   143 Connecting line    -   146 Gas drying apparatus    -   146A Line    -   150 Vacuum unit    -   151 Second switchover valve block    -   151A Pressure switch    -   152A Pressure reducer    -   152B Pressure reducer    -   153 Flushing medium tank    -   154 Filter    -   155 Inspection window    -   156 (Second) oil separator    -   156A,C Shut-off valves    -   157A Connecting line    -   157B Connecting line    -   157C Line region    -   158 Shut-off valve    -   159 Coupler    -   160 Evacuating line    -   161 Gas analyzer    -   161A Gas analysis connection    -   161B Shut-off valve    -   162A/B Connector

1. A servicing device for vehicle air-conditioning systems comprising anemptying device for extracting the refrigerant/compressor oil mixturefrom the refrigerant circuit system of a vehicle air-conditioningsystem, and a refrigerant gas analyzer, characterized in that a gasanalysis connection is provided on or in at least one of the connectinglines between the servicing device and the vehicle air-conditioningsystem, which gas analysis connection) is connected or can be connectedfluidically to the gas analyzer for refrigerant via an oil separatorwhich can be evacuated and is connected at least temporarily to anevacuating device.
 2. The servicing device as claimed in claim 1,characterized in that the oil separator can be connected or istemporarily connected fluidically to a separator stage forrefrigerant/compressor oil mixture.
 3. The servicing device as claimedin claim 1, characterized in that the region of the connecting linesbetween the oil separator and servicing connection connectors can beemptied of refrigerant/compressor oil mixture via connectors
 4. A methodfor the upstream refrigerant gas analysis in servicing devices forvehicle air-conditioning systems, characterized in that a sample ofrefrigerant/compressor oil mixture from the vehicle air-conditioningsystem is transferred from the vehicle air-conditioning system into apreviously evacuated oil separator and, after the connecting line to thevehicle air-conditioning system is closed again and, after a separationinto a gas phase and a liquid phase which is carried out in the oilseparator, the gas phase region is connected to the gas analyzer forrefrigerant analysis.
 5. The method as claimed in claim 6, characterizedin that the oil separator which is connected upstream of the gasanalyzer is connected to a separator stage for refrigerant/compressoroil mixture which comes from the vehicle air-conditioning system, withthe result that the sample volume, drawn for the purpose of gasanalysis, of refrigerant/compressor oil mixture from the vehicleair-conditioning system is treated further.
 6. The method as claimed inclaim 4, characterized in that refrigerant/compressor oil mixture whichis not accepted by the gas analyzer is discharged separately from theoil separator and the connecting lines to the vehicle air-conditioningsystem and from the vehicle air-conditioning system, without coming intocontact with the remaining lines and containers which are present in theservicing device for refrigerant and/or compressor oil.
 7. The servicingdevice as claimed in claim 2, characterized in that the region of theconnecting lines between the oil separator and servicing connectionconnectors of the servicing device can be emptied ofrefrigerant/compressor oil mixture via connectors.
 8. The method asclaimed in claim 5, characterized in that refrigerant/compressor oilmixture which is not accepted by the gas analyzer is dischargedseparately from the oil separator and the connecting lines to thevehicle air-conditioning system and from the vehicle air-conditioningsystem, without coming into contact with the remaining lines andcontainers which are present in the servicing device for refrigerantand/or compressor oil.